The present invention relates to an anorthite sintered body and a process for the preparation thereof.
As the electric insulator for electronic parts such as an IC package, a sintered body of an inorganic powder such as alumina is most widely used since this sintered body is excellent in electrical characteristics and mechanical characteristics. Recently, sintered bodies of this type are often manufactured according to the so-called cofiring technique of printing an electronic circuit on a formed body of an inorganic powder before sintering by using an electroconductive substance and sintering the formed body to form an electrically insulating material having a circuit printed thereon. However, this technique is defective in that since a high temperature is generally required for sintering an inorganic powder, the printing cannot be accomplished without using an expensive electroconductive substance capable of resisting such a high temperature. For example, in case of an alumina powder, since a sintering temperature higher than 1500.degree. C. is necessary, an expensive electroconductive substance such as Mo, Mn, or W has to be used. Moreover, electroconductive substances of this type are not sufficiently satisfactory in the electrical conductivity. Accordingly, investigations have been made to find out a sintered body capable of being cofired with a substance having a good electrical conductivity, such as Ag, Au or Cu, and a variety of low-temperature sintered bodies have been proposed. However, a technique of preparing a low-temperature sintered body industrially stably at a low manufacturing cost has not been established.